Tensioning device



Jan. 25,1927;

F. J. MARTHY' TENSIONING DEYICE Filed March 25 1925 jig. l.

INVENTOR Francis K]. Martha %wfl% ATTORNEYS Patented Jan. 25, 1927.

UNITED sir-Ares FRANCIS J. MARTHY, or HAZIJETON, PENNSYLVANIA.

'TENSIONING DEVICE.

Application fled March 25, 1925. Serial No. 18,205.

This invention relates to tensioning devices ada-pted to be employed incombination with timing pinsfor piano strings.

The tuning pin of an instrument is ordinarily mounted within an openingprovided in the wrest plank or pin block but such opening becomesenlarged due to the to tation of the pin during tuning and also due tostrains caused by the tension of the string so that it is diflicult tohold the pin against rotation after a predeterminet l {number oftunings. Because of such detectin the pin blocki-t is necessary to setthe pins but such setting seldom if ever can be effected after anylength of time because of the-defective wrest planks and becauseot thetwisting of the pins.

Anobject of the invention is the provision of adevice adapted to beemployed in connection'with tuning pins whereby the strings oftheinstrument'may be easily, accurately andfinely'adjusted andsecurely-held in their adjusted positions.

A. further object ot thc invention is the provision of a device adaptedto be employed in connection withtuniug pins for {pianos'and in whichthe pin is held against movement after its adjustment and upon which ismounted a removable sleeve to which the string *is secured for finelyadjusting the *tension of the strings which will maintain the tension.

This invention will be best understood from a consideration of thefollowing detailed description, in view I of the accompanying drawingsforming a part of the specification; nevertheless it is to be understoodthat the invention is not confined to the disclosure, being susceptibleof such changesand modificationswhich sha l-l define no materialdeparture from the salient features of the invention as expressed in theappended claims.

In the drawings:

Figure 1 is a fragmentary view in elevation showin my invention appliedto the metal plate of the piano.

Figure 2 is a transverse vertical section taken through one of the pins.

Figure 3 is a View in perspective of the preterred form of my inventionshowing the parts in detached relation.

Figure Lisa view in perspective ota modified form of the invention.

Figure 5 is a view showing the modified form of the invention shown inFig. 4 as applied to the usual makes of the pianos now in use.

Figure 6 is a "view in perspective ot'the sleeve'a-ssociated with thepins shown in Figures 4t and 5.

- Referring more particularly to the drawings, 10 designates a metalplate 01 a piano whichis provided with a plurality of sleeves 11integrally formedw-i tl'i the plate. llaoh of the sleeves is providedwith 'a passage 12 1n which is mounted a timing pin 13. This pin has oneend threaded as shown at 14 adapted to receive a nut 15 which engages awasher 16 abutting a shoulder 40 on the pin 13 so that the washer isslightly spaced from the free end of the sleeve. The pin 13 has atoothed wheel or flange 17 rigidly attached thereto and adapted toengage the outer face of the metal plate 10 and cooperate with the nutl5to prevent displacementot said pin.

A spring pressed pawl 18 secured to the metal plate 10 is adapted toengage the teeth of the flange 17 and lock the pinagainst rotation.

The pin at 19 is provided with a spiral screw or thread w lric h is ofthe multiple trapezoidal or square thread with considerable pitc'h. I

Mounted on the threaded portion if) is a sleeve 20 having a collar '21in which is formed a recess or countersunk portion 22 adapted to receivea hub 23 on a 'nut 24; which engages the threads 25 on the pin 19. Thesleeve '20 is provided with threads 26 adapted to engage the threads onthe portion 19 of the pin. The pin at its outer extreme end is square incross section as shown at 27 which is adapted to be engaged by anysuitable tool. The nut 24 has a hexagonal conformation likewise adaptedto be engaged by a suitable tool for'turning the same. The collar 21 isprovided with a perforation 28 in which is adapted to be inserted theend of a piano string 29.

In Figure 4 is shown a modified form of the invention and in which theportion 19 is devoid of threads but provided with a pin 30 whichprojects laterally from diametrically oppositc points and which projectsthrough curved slots 31 in a sleeve 32. The sleeve 32 has a collarprovided with a perforation 34: adapted to receive a piano wire 29. Thecollar 33 is located inter- Lil mediate the ends of the sleeve 32. Thepin 13 in this case is also provided with a threaded end i l, a threadedportion :25 adapted to be engaged by a nut tor adjusting and locking thesleeve 32 against movement. The end of the pin is square in crosssection adapted to be engaged by any suitable tool. The toothed annularflange ii is also employed and is adapted to be engaged by the pawls 18with the inner end of the sleeve 32 abutting the member 17.

In Figure 5 is shown the modilied 'l'orm secured to the metal plate ofthe piano whereby the usual terms of metal plates may be adapted withthe present invention. in such a case an enlarged opening 35 is providedin the plate lit through which is inserted a metal sleeve 11. Thissleeve is provided with a flange 36 upon which is pivotally mounted aspring pressed pawl 3. adapted to engage the teeth of a" annular flange17 formed integrally with the pin 13. The sleeve 11 is externallythreaded and a nut 38 engaging the threads on the sleeve is adapted tolock the sleeve to the metal plate in conjunction with the annularflange 36. The pin 13 has a threaded 'end 1st upon which is screwed anut 15 for forcing the washer 16 in rigid engagement with the shoulder%0 on the inner end of the pin 10. The washer 16 and wheel or flange 17cooperate to prevent displacement of the pin.

The operation of my device is as follows:

Either construction as shown in Figure or 5 may be employed and the pins13 or 13 are locked in place as has been explained by means of thetoothed annular flange 1'? and the nut 15 and washer 16 with the nutlocated at one end of the sleeve 11 or 11 and the toothed flange 1'7 inengagement with one face of the metal plate 10 or 10 The pin 13 or 13 isrotated in the usual manner until substantially the pitch of the stringis had whence the nut 2% is turned until the proper tension is placedupon the string to produce the exact tone desired. The nut 24:trictionally engaging the end of the sleeve 20 or the sleeve 32 causesthe sleeve to be turned and since the string is secured to the sleevethe string will be further tcnsioned. As the nut 24: is revolved in theconstruction shown in Figure 3 the sleeve is also rotated to itsengagement with the threads on the portion 15) ot' the pin while inFigure 4t the sleeve is revolved and maintained in its adjusted positionthrough the pins moving through the arcuately shaped slots 31 of thesleeve 32.

Having described the invention, this is claimed:

1. A tensioning device for piano strings comprising a tuning pin, asleeve mounted on the pin for independent rotation, means foroperatively connecting the sleeve with the pin so that the sleeve may berevolved with the pin, and a nut threaded on the pin to trietionallycontact with the sleeve for causing rotation of the sleeve independentlyof the pin when the nut is rotated, and means included in the pin, nutand sleeve for causing a dill'erential speed of rotation between the nutand the sleeve.

2. A tensioning device for piano strings comprising a tunin pin, asleeve mounted on the pin tor independent rotation, means foroperatively connecting the sleeve with the pin so that the sleeve may berevolved with the pin, and a nut threaded on the pin to trictionallycontact with the sleeve for causing rotation of the sleeve independentlyof the pin when the nut rotated, means for locking the pin againstrotation in one direction, and means included in the pin, nut and sleevefor causing a differential speed of rotation between the nut and thesleeve.

3. A tensioning device for piano strings comprising a tuning pin, asleeve mounted on the pin for independent rotation, means foroperatively connecting the sleeve with the pin so that the sleeve may berevolved with the pin, and a nut threaded on the pin to trictionallycontact with the sleeve for causing rotation of the sleeve independentlyout the pin when the nut is rotated, said sleeve being provided withmeans for securing the piano string to the same whereby the end of thepiano string will be coiled on the sleeve during tensioning of thestring, the operative means which connects the sleeve with the pin beingconstructed to cause a differential speed of rotation between the nutand the sleeve.

t. A tensioning device for piano strings comprising a metal plateprovided with a plurality of hollow sleeves projecting rearwardly fromsaid plate, a tuning pin mounted in each sleeve, the tuning pin beingprovided with a ratchet wheel forming a shoulder to engage one face ofthe metal plate, means cooperating with the wheel to preventdisplacement of the pin from a sleeve, pawls to engage the ratchet wheelfor preventing rotation of the pin in one direction, a sleeve rotatablymounted on the pin, and cooperating means on the pin and the sleeve forcausing the sleeve to be moved longitudinally of the pin and permittingindependent rotation of the sleeve on said pin, a nut threaded on thepin adapted to trictionally contact with the sleeve so that when the nutis rotated the sleeve will be revolved independently of the pin, andmeans for securing a piano string to the sleeve.

5. A tensioning device for piano strings comprising a metal plateprovided with a plurality of hollow sleeves projecting rearwardly fromsaid plate, a tuning pin mounted in each sleeve, the tuning pin beingprovided with a ratchet wheel forming a shoulder to engage one face ofthe metal plate, means cooperating with the wheel to preventdisplacement of the pin from a sleeve, pawls to engage the ratchet Wheelfor preventing rotation of the pin in one direction, a sleeve rotatablymounted on the pin, cooperating threads on the pin and on the sleeve forcausing the sleeve to be moved longitudinally of the pin and permittingindependent rotation of the sleeve on said pin, a nut threaded on thepin to frictionally contact with the sleeve so that when the nut isrotated the sleeve will be revolved independently of the pin, and meansfor securing a piano string to the sleeve.

6. A tensioning device for piano strings comprising a metal plateprovided with a plurality of hollow sleeves projecting rearwardly fromsaid plate, a tuning pin mounted in each sleeve, the tuning pin beingprovided with a ratchet wheel forming a shoulder to engage one face ofthe metal plate, an end of the pin being threaded and. a nut screwedonto the threaded end of the pin for cooperating with the ratchet Wheelto prevent displacement of the pin from the sleeve, pawls to engage theratchet wheel for preventing rotation of the pin in one direction, asleeve rotatably mounted on the pin, and cooperating means on the pinand the sleeve for causing the sleeve to be moved longitudinally of thepin and permitting independent rotation of the sleeve on said pin, a nutthreaded on the pin adapted to fric tionally contact with the sleeve sothat when the nut is rotated the sleeve will be revolved independentlyof the pin, and means for securing a piano string to the sleeve.

In testimony whereof I afiix my signature.

DR. FRANCIS J. MARTHY.

